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Tell Me About Your 3-blade Prop

RV7ator

Well Known Member
I'm considering a 3-blade prop for my latest RV-7 build. I'm curious about how much of a PITA it is lowering the cowl with a 3-blade and no assistant. 2-blades have been the norm for prior planes. With two blades, all I need do is protect the lower spinner edge from cowl scrapes with tape. The installation will be a M1B, snorkel on a Superior sump, standard Van's (no Sam James, etc) cowl.

Any anecdotes you'd like to share?

John Siebold
 
3 Blade Catto and it's a PITA to get the lower off without a helper. It's much easier if you have a tail dragger, my the nose wheel makes it tough. You'll find a method that works for you and then it's not that bad, but not easy. I use a towel draped over the nose gear leg to protect it from scratches when the cowl runs down it.

Also getting it to clear the blades takes careful Turing of the prop in both directions as you lower the cowl down.
 
Should be no problem on a -7. I had one on my -6 and had no difficulty at all.

The only people that have problems are those who have the tailwheel on the wrong end.
 
John

I know it doesn't answer your question....but.

I just ordered my Catto 3 blade prop with clear coat carbon spinner. White w/red tips, leading edge tape.

Rv7, long James cowl. Can't wait to get it.

Arnie
 
Should be no problem on a -7. I had one on my -6 and had no difficulty at all.

The only people that have problems are those who have the tailwheel on the wrong end.

I agree with Mel. Mine was a 7A and I needed to flex the cowl to get it off. I was able to do it without help but it was, as noted, a PITA. I had the longish Sam James cowl, btw. Part of the problem was, of course, the nose wheel "leg".

I don't see where there would be a problem with a 7.

The problem is that you have to slide the cowl forward. I had to lengthen the slot for the gear leg so I could lower it enough to clear the part of the 3-blade hanging down.
 

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MT 3 blade on an RV7 with a snorkel.

Absolutely no issues - needs 2 people to make it super easy, but can be done single handed.

No idea why people are questioning it :rolleyes:
 
I’ve got two RV’s (both taildraggers) with 3-Blade Whirlwinds, and usually just put the cowls on and off alone - no problem at all.
 
New gear

The new nose gear I think will make this considerably easier. The slot and lower cowl mount is different then the old cowl for the old nose gear.

I will be there in a few weeks, so I will let you all know how it goes.
 
MT 3 blade on an RV7 with a snorkel.

Absolutely no issues - needs 2 people to make it super easy, but can be done single handed.

No idea why people are questioning it :rolleyes:

Same setup, no issues. Do yourself a favor and leave a little extra room between the cowl/spinner.
 
I'm considering a 3-blade prop for my latest RV-7 build. I'm curious about how much of a PITA it is lowering the cowl with a 3-blade and no assistant. 2-blades have been the norm for prior planes. With two blades, all I need do is protect the lower spinner edge from cowl scrapes with tape. The installation will be a M1B, snorkel on a Superior sump, standard Van's (no Sam James, etc) cowl.

Any anecdotes you'd like to share?

John Siebold

The benefits of the 3-blade prop far outweigh the so-called PITA when removing the cowl. george
 
WhirlWind 3 blade

Maybe the 14A is a different set-up but I found no issues removing top or bottom cowling. I use the Anti Splat fairing protector but painters tape would also work. I do apply painters tape around the spinner as my clearances are pretty tight but only takes a few minutes. I found zero issues with the 3 bladed prop on the 14.
 
My 6A had a Catto 3 blade and now a MT 3 blade. I find it easier to get the bottom cowl off by myself than with help. I turn the nose gear all the way one way or the other and the cowl comes down easily.
 
Going 3-Blade

Thanks, guys. You've reinforced my impression that having a properly located center wheel is critical for ease of removal. Walt's mention of a bigger spinner-cowl gap is words to the wise. I've been setting mine 3/8-7/16, never missed the forecast 30k TAS hit, and no tools have been thrown.

Ironflight, I read your Whirl Wind 300-72 v. BA comparison. I'm going with the 300-72. They look cool for a $3,500 up charge over the BA, but also available! Last week WW quoted 10-12 weeks, Van's (BA) 6-10 months, leaning toward 10!

John Siebold
 
One person

By the way I find doing it myself easier and more predictable than getting “help”. It’s really not an issue. Keep the gap close. The bottom cowl can drop vertically down till it hits the Anti Splat protector and just slides down and forward. Hoping the 15 in. spinner on the 10 the same.
 
I have a catto 3B on my 8 and its no big deal to remove the cowl solo. It's easier with a helper, but no always an option. Nose gear would make it harder, but tail dragger is fine.
 
Maybe the 14A is a different set-up but I found no issues removing top or bottom cowling

Did you have to increase the length of the slot (forward of the gear leg) compared to what the plans specify for the -14A? If so, by how much?
 
I have a catto 3 blade...it is great, but never ran a 2 blade for comparison. You need to retorque the hub bolts at least every 6 months....but I just remove the prop and lower cowl every 4 months or so at oil change time....yes, it is a little more time consuming, but you get to give everything a good look with that procedure.

Paul RV7A
 
One other approach to making the bottom cowl removal easier on the RV-10 is to make the combustion air intake scoop removable. You basically cut it out and install a fiberglass flange to allow it to be attached with screws into nut plates. It's a fairly simple job (took me about 6-7 hrs over 2 days), and makes the bottom cowl removal/installation much easier, particularly with a 3 blade prop. I also know several RV-10 builders who did this with their 2 blade props and highly recommend it.

I suspect the same thing could be done for the RV-14a or other models.

Cheers,
 
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One other approach to making the bottom cowl removal easier on the RV-10 is to make the combustion air intake scoop removable. You basically cut it out and install a fiberglass flange to allow it to be attached with screws into nut plates. It's a fairly simple job (took me about 6-7 hrs over 2 days), and makes the bottom cowl removal/installation much easier, particularly with a 3 blade prop. I also know several RV-10 builders who did this with their 2 blade props and highly recommend it.

I suspect the same thing could be done for the RV-14a or other models.

There's no scoop on the RV-14(A) series, they all have a smooth lower cowl with snorkel intake.
 
I’m putting a sterna on my 6A, I will let you know how it goes. Hopefully the cowl removal Isn’t to painful with it on.
 

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Gap for a 14A

Did you have to increase the length of the slot (forward of the gear leg) compared to what the plans specify for the -14A? If so, by how much

I don’t remember adding more gap. Picture attached. (If I’m smart enough to do this on my Iphone) The current gap is 2 inches.
 

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Cowling removal

After receiving a few requests for a video how to take canopy on and off with an A model and 3 bladed WW prop I thought I would try and document my procedure. If I can do it anyone can. My set-up is all hinge pins, three bladed prop, do not have a split bottom cowl. Stock Vans cowling on my 14.
1) Using painters’ tape, tape off the spinner to cowling attaching painters’ tape to the spinner flange to protect it, 4 pieces of 2 inch wide painters tape can protect the entire 360 degrees of the spinner to cowling interface.
2) Again, using painters’ tape, tape off the top portion of the bottom 2 blades. The third blade should be pointed straight up. You need to also protect the nose wheel fairing. Anti-splat sells a device or use painters’ tape or better yet use 2-inch L cardboard taped in place, this can also be used to protect the propeller blades.
3) Remove the top cowling by removing the side hinge pins clips or insets then pulling the side hinge pins, under the cowling top hinge pins next. Then 4 screws around the spinner that hold top cowling to bottom cowling.
4) Remove bottom screws. Now carefully remove one side of the bottom cowling hinge pin and allow one side to drop down 3 to 4 hinge pin sections. Reinsert the side hinge pin. Go to the other side and drop down 5 to 6 hinge pin sections and reinsert the side hinge pin. Go to the other side remove the side hinge pin and let the canopy rest on the nose wheel protector piece. Do the same for the other side. The key is to drop the bottom canopy straight down until the bottom rests on the nose wheel strut. Once you are there the canopy can slide down the strut keeping the cowling horizontal during the slide. If a non-A model I guess you can just drop straight down.
5) To put the canopies back on reverse the process but always, always apply BoLube to the pins. Even if you did it 2 weeks ago reapply BoLube. It makes a huge difference !!!
6) For me the hardest pins to put back in are the top back under the upper cowling pins. I found it easiest to get in from the side since I seem to be at a good height. I’m pretty tall so shorter people might need some elevation but not much. To high and I find it difficult to hold the pin while inserting the tip. Again make sure these pins are well lube, it’s critical.
 
Starboard side upper cowling hinge pin RV-14 tool

This is the hinge pin that seems to give the most issues reinstalling. (Previous post) The oil access door is barely large enough for some of our arms to fit in and you need to hold the hinge pin by the tip to inset. It's easy to drop. I made this up about a year ago and has helped (At least me) re-insert the pin into the hinge. It allows one to control the far end and reduce the risk of dropping it or getting hung up. See attached pic.
 

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